Question

In the circuit arrangement shown, if the point $A$ and $B$ are joined by a wire the current in this wire will be:

• A. $1A$
• B. $2A$
• C. $4A$
• D. Zero

Answer 1

The correct option is D Zero

Answer is D.
Wheat stone bridge is an electrical circuit . In wheat-stone bridge four resistances R1, R2, R3 and R4 are connected end to end with each other to form a closed loop.
In a balanced condition, the four resistances in the circuit are of the same value and the current at the mid points of the circuit is always zero. That is, the potential VA of point A is equal to the potential VB at point B. VA - VB = 0.
Hence, if the point A and B are joined by a wire the current in this wire will be 0.